1. The handy preview page, handy because as you can see there's a Barclays logo, chip, Visa logo and writing which go on top of your image. I cropped the card picture down and outlines all areas where the card was covered so that my new image would be too badly masked.
2. Template with approximate covered areas, use this as a layer in your favorite image program. The following photos still have the mask layer but i'd remove it before actually using any of them.
3. Pin out for ATMega 328P for bread boarding an Arduino. Might need a magnifying glass to read?
4. London underground map from http://www.tubemaplondon.org/
Some information is lost, but if you are at a tube station there would be a map but these maps are in every diary so somebody must use them? Anyway, too small to read but gives an idea of line intersections.
5. Resistor calculator pic (from http://learn.adafruit.com/multimeters/resistance) - This was the nicest resistor calc image I saw on Google images, it's my favorite so far, but not yet perfect, needs to be redrawn to fit around the text.
6. Passport to awesome - a raspberry pi! (from http://blog.modmypi.com/)
7. Pi GPIO
I'll post more ideas as they occur and please post pics in the comments :D
Other ideas I can't quite get to fit or almost don't quite work:
-TO DO list - use a marker and some ethanol to clean
-A big warning sign making me reconsider spending money :D
-Allergy information and emergency contact numbers
-Instructions on how to jimmy a lock with a credit card